| Zigrasolabis | |
|---|---|
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Dermaptera |
| Family: | Labiduridae |
| Genus: | †Zigrasolabis |
| Species: | †Z. speciosa |
| Binomial name | |
| †Zigrasolabis speciosa | |
Zigrasolabis is anextinctgenus ofearwig in the familyLabiduridae known fromCretaceous fossils found inMyanmar. The genus contains a single described species,Zigrasolabis speciosa.[1]
Zigrasolabis is known from a group of fossils, theholotype, specimen number JZC-Bu232, along with twoparatypes and a partial specimen. The specimens are composed of three fully complete adult female earwigs, and the partial female, which have been preserved asinclusions in a single transparent chunk ofBurmese amber.[1] The age of the amber deposits inKachin State in northernmost Burma is understood to be at least 100 million years old, placing them in theAlbian age of the Cretaceous.[2] As of 2014, Burmese amber has beenradiometrically dated usingU-Pb isotopes, yielding an age of approximately 99 million years old, close to theAptian –Cenomanian boundary.[3] At the time of description, the amber specimen was residing in the private collection of James Zigras and only available for study through theAmerican Museum of Natural History.
TheZigrasolabis type specimens, recovered from amber bearing outcrops inKachin State, were first studied by paleoentomologistsMichael S. Engel of the Division of Entomology at theUniversity of Kansas, andDavid Grimaldi of the American Museum of Natural History.[1] Engel and Grimaldi's 2014type description of the new species was published in the journalNovitates Paleoentomologicae.[1] The genus nameZigrasolabis was coined by Engel and Grimaldi as a combination ofGreek wordlabis, which means "forceps" and Zigras in honor of James Zigras. Thespecific epithetspeciosa is from the Latin wordspeciosus, which translate as "splendid".Zigrasolabis is one of six described earwig species found in Burmese amber. A second species,Toxolabis zigrasi was also described by Engel and Grimaldi in 2014 paper. Two speciesAstreptolabis ethirosomatia andTytthodiplatys mecynocercus were described by Engel in the same 2011 paper, whileBurmapygia resinata was described by Engel andDavid Grimaldi in 2004, with the last speciesMyrrholabia electrina first described byTheodore Cockerell in 1920.[4][1]
FemaleZigrasolabis have and overallcoloration that appears to be mat brown to dark brown, lightening on the legs and mouth parts. The females range between approximately 8.0–8.3 millimetres (0.31–0.33 in) in length when the cerci are included. The bodies are only sparsely covered insetae, which are not thickened enough to be chaetulose. The antennae have a slightly widescape and are at least fourteenflagellomeres long, though both the holotype and the paratypes have incomplete antennae. As is typical with earwigs, theforewings have been modified intotegma which cover the first segments of the abdomen. The hind wings are present, but due to positioning of the tegma, are mostly obscured, though the tips extend beyond the tegma. The slender cerci are tubular and straight, tapering along the length to sharp points at the ends.[1]